Several studies have reported a favorable effect following the administration of growth factors during the course of acute renal failure. To evaluate the effect of an increased endogenous production of growth factors, rats underwent 70% hepatectomy before glycerol-induced acute renal failure. The renal function was then monitored 12 and 48 h after glycerol injection in conscious rats. Twelve hours after the induction of acute renal failure, a reduction in creatinine clearance and sodium reabsorption was seen in both prehepatectomized and sham-hepatectomized rats. At 48 h, there was total recovery of glomerular filtration and tubular function in the prehepatectomized rats, whereas the sham-hepatectomized rats still had reduced glomerular filtration and sodium reabsorption. In rats treated with dexamethasone before hepatectomy and studied 48 h after the induction of acute renal failure, the protective action on renal function seen in prehepatectomized rats was totally blocked. A semiquantitative histological analysis done 48 h after the induction of acute renal failure demonstrated a fourfold increase in the number of necrotic tubules in both sham-hepatectomized and dexamethasone-treated rats as compared with hepatectomized rats. It is concluded that partial hepatectomy, a maneuver used to increase the endogenous synthesis of growth factors, accelerates recovery of renal function following glycerol-induced acute renal failure.